Patent GB-582930-A (GB)
Title: Method of and apparatus for ejecting liquid from aircraft in flight for producing visible effects in the air
IPC: F41H9/06
Filed: 1931-08-22
Abstract: 582,930. Discharging liquids by gas pressure. STEWART, C. J., FRY, J. D., and JAQUES, C. N. Aug. 22, 1931, No. 23630. [Class 102 (ii)] [Also in Groups VI and XXI] Relates to apparatus for ejecting liquid from aircraft in flight, for producing smoke curtains or the like, of the kind in which the liquid is ejected from a container by air or other gas under pressure. According to the invention, the container, connected through a discharge cock to a nozzle, is partly filled with liquid, and the gas under pressure occupies the remaining space in the container (or in a separate vessel communicating therewith), the ratio of air-space to liquid-space and the pressure being so chosen that the initial jet velocity exceeds the speed of the aircraft by a desired amount and, the pressure having decreased as the liquid is ejected, the final jet velocity is less, by a required amount,-than the aircraft speed. The. apparatus shown comprises a solid-drawn cylindrical container 1, one end of which is formed as a removable plate 5 through which a liquid pipe 7 and an air pipe 12 extend. A flanged nut 8, Fig. 4, screwed on to the liquid pipe, is bolted to the plate 5 and is adapted for connection to a cock 11. A flanged sleeve 15 is sweated on to the air pipe 12, and has mounted on it a gland 16 which screws into the plate 5, a union sleeve 19 being screwed on to the end of the sleeve 15 projecting through the gland. An adaptor 22, for connecting an aircock, is screwed into the sleeve 19, and clamps against a shoulder in the sleeve 19 a disc or septum 24 of German silver. This septum is in contact with a cutting edge 23 on a ring 20, located in the union sleeve and carrying a diametral bridge piece 21. A similar bridged ring with a cutting edge and a septum are located at 25 between the liquid pipe 7 and the cock 11. The septum is in this case supported by oil or other liquid on the side nearer to the cock. A tube 28, Fig. 2, for receiving a thermometer, may extend through the plate 5. A removable cap 26, Fig. 4, is provided to protect the fittings on the end plate 5 when the apparatus is in transit or not in use. The container may be supported centrally under the fuselage A of the aircraft, with the end plate at the tail end, as shown in Fig. 11. The liquid cock 11 is coupled to a discharge pipe 33, which extends towards the mid-length of the wing B, where the pipe is bent and extends aft to a downwardly-inclined discharge nozzle 35. The cock 11 may be operated from the pilot's seat by control mechanism. The container having been charged to the required extent with liquid, either before or after being placed in position on the aircraft, the liquid-discharge cock and an airsupply cock are applied, with the pipes sealed by the' septa. For charging with compressed air, an air supply is connected through the aircock to pipe 12, and the septum 24 breaks down, being cut by the edge of the ring 20; the septum folds over the bridge 21 and thus leaves the passage free. The air cock is then closed. When the liquid-cock is opened to allow the compressed air to discharge the liquid, its associated septum is' no longer supported by the oil &c. on the side remote from the container, and is broken down by the pressure in the container, folding over the bridge in the discharge pipe and leaving the passage unobstructed.